The present invention relates to an electronic system and components thereof for remotely controlling a locomotive. The system has a tilt sensor designed to operate in conjunction with a processor onboard a locomotive in order to detect when a portable controller has an inclination outside a normal range of inclinations.
Economic constraints have led railway companies to develop portable master controllers allowing a ground-based operator to remotely control a locomotive in a switching yard. The portable master controller has a transmitter communicating with a slave controller on the locomotive by way of a radio link. To enhance safety, the portable master controller carried by the operator is provided with a tilt-sensing device to monitor the spatial orientation of the portable master controller and determine occurrence of operator incapacitating events, such as the operator tripping and falling over objects and loss of conscience due to a medical condition, among others.
Tilt sensing devices generally interact with a processing unit mounted in the portable master controller to detect when the tilt-sensing device reports that the portable master controller is outside the normal range of inclination. When the tilt-sensing device reports that the portable master controller is outside the normal range of inclination, the processing unit in the portable master controller will automatically generate, without operator input, a command signal over the radio link to stop the locomotive.
The portable master controllers are carried by the train operators and, as such, it is desirable for these portable master controllers to be light in order to avoid any unnecessary strain and/or injury to the operators. The above-described system requires that the portable master controllers be equipped with additional processing capabilities to process the inclination information and, as such, usually requires additional components to support this processing capability.
Against this background, the reader will appreciate that a clear need exists in the industry to develop a system and components thereof for remotely controlling a locomotive, featuring tilt-sensing devices which overcomes at least part of the deficiencies associated with the prior art.
In accordance with a broad aspect, the invention provides a portable master controller for a locomotive remote control system where the locomotive remote control system has a slave controller mounted on-board a locomotive. The portable master controller includes a user interface, a tilt sensor, a processing unit and a transmission unit. The user interface receives commands to control movement of the locomotive from a human operator. In response to a command from the human operator, the user interface generates a control signal. The tilt sensor generates inclination information about the portable master controller. The processing unit, which is in communication with the user interface and with the tilt sensor, generates a digital command signal for directing the movement of the locomotive. The digital command signal includes a first component derived from the control signal received from the user interface for directing the movement of the locomotive and a second component derived from the inclination information received from the tilt sensor. The second component of the digital command signal can be used to determine whether the portable master controller is in an unsafe operational condition. The transmission unit, which is in communication with the processing unit, receives the digital command signal and generates a RF transmission conveying the digital command signal to a slave controller.
Advantageously, the inclination information obtained from the tilt sensor can be transmitted to the slave controller such that the determination of whether the master controller is in a safe or unsafe position can take place at the slave controller. This allows a reduction in computations that must be effect by the master controller. The transmission of inclination information along with control signal allows the slave controller to validate the digital command signal in part on the basis of the inclination information. For example, in the case where the command signal is instructing the locomotive to accelerate, and the inclination information indicates that the master controller is severely tipped, then the slave controller will not implement the command signal and perform a default safety operation instead.
In a first specific example of implementation, the tilt-sensing device in the portable master controllers is in the form of a solid-state tilt sensor. By xe2x80x9csolid-statexe2x80x9d is meant a tilt sensor that does not uses a liquid to produce inclination information. In a specific and non-limiting example of implementation, the solid-state tilt sensor includes a single axis accelerometer responsive to the acceleration of gravity. Optionally, the accelerometer is a multi-axis device responding to vertical acceleration and acceleration in at least another axis, as well. The ability to assess acceleration levels in axes other than the vertical axis permits detection of unsafe conditions that do not necessarily translate into an excessive inclination of the portable master controller.
In a second specific example of implementation, the tilt-sensing device in the portable master controllers is in the form of a mercury switch.
In accordance with a second broad aspect, the invention provides a slave controller for a locomotive remote control system where the locomotive remote control system also includes a portable master controller adapted for issuing RF transmissions conveying digital command signals to the slave controller. The slave controller is suitable for mounting onboard a locomotive and includes a receiver module and a processing unit. The receiver module is suitable for receiving an RF transmission conveying a digital command signal from a portable master controller. The digital command signal includes a first component indicative of a command for directing the movement of the locomotive and a second component indicative of inclination information. The processing unit, which is in communication with the receiver module, is responsive to digital command signals to determine, on the basis of the inclination information, if the portable master controller which transmitted the digital command signal is in a safe operational condition or in an unsafe operational condition. When the processing unit determines that the portable master controller is in an unsafe operational condition, the processing unit generates a local emergency command signal for directing the locomotive to acquire a secure condition. When the processing unit determines that the portable master controller is in a safe operational condition, the processing unit generates local signals controlling the locomotive on the basis of the first component of the digital command signal.
In a specific example of implementation, a xe2x80x9csecurexe2x80x9d condition is a condition in which the risk of accident from the locomotive is substantially reduced. An example of a secure condition is the locomotive being stopped. In such an example, the local emergency command signal directs the locomotive to stop.
In another broad aspect, the invention provides a remote control system for a locomotive including in combination the portable master controller defined broadly above and the slave controller for mounting on-board the locomotive also defined broadly above.
In accordance with another broad aspect, the invention provides a portable master controller for a locomotive remote control system, where the locomotive remote control system has a slave controller mounted on-board a locomotive. The portable master controller includes a user interface, a tilt sensor a processing unit and a transmission unit. The user interface is for receiving commands to control movement of the locomotive from a human operator. The user interface is responsive to a command from the human operator to generate a control signal. The tilt sensor generates inclination information about the portable master controller. The processing unit generates a command signal for directing the movement of the locomotive and an inclination indicator signal derived from the inclination information. The inclination indicator signal allows a slave controller to determine whether the portable master controller is in an unsafe operational condition. The transmission unit receives the command signal and generates a first RF transmission directed to a slave controller conveying the command signal to the slave controller. The transmission unit receives the inclination indicator signal and generates a second RF transmission directed to the slave controller conveying the inclination indicator signal.
In a specific example of implementation, the transmission unit transmits the first RF transmission at a first transmission rate and the second RF transmission conveying the inclination indicator signal at a second transmission rate different from the first transmission rate. On the basis of this inclination information, the slave controller can determine whether the master controller is in a safe or unsafe position. The slave controller can then cause the locomotive to acquire a secure condition in the cases where it is determined that the master controller is in an unsafe position. This specific implementation allows for transmitting to the slave controller the inclination information obtained from the tilt sensor separately from the command signals for controlling the locomotive. Optionally, the inclination indicator signal and the command signal may be transmitted over separate RF channels.
In accordance with another broad aspect, the invention provides a slave controller for a locomotive remote control system, where the locomotive remote control system has a portable master controller adapted for generating RF transmissions to the slave controller. The slave controller is suitable for mounting onboard a locomotive and includes a receiver module and a processing unit. The receiver module is suitable for receiving RF transmissions conveying digital command signals including a command signal for directing movement of the locomotive and an inclination indicator signal. The processing unit determines at least in part on the basis of the inclination indicator signal if the portable master controller, which transmitted the digital command signal, is in a safe operational condition or in an unsafe operational condition. When the processing unit determines that the portable master controller is in an unsafe operational condition, the processing unit generates a local emergency command signal for directing the locomotive to acquire a secure condition. When the processing unit determines that the portable master controller is in a safe operational condition, the processing unit generates local signals for controlling the locomotive on the basis of the command signal.
In a specific implementation the inclination indicator signal and the command signal are received over separate RF channels.